1. Field of the Invention
This invention relates to a workpiece holding device, especially to a cloth holders for a sewing machine.
2. Prior Art
It is known that pocket edge folding operation is executed as follows in a prior art device.
In response to various contour of a patch pocket, a plurality of workpiece holding plates such as gage plates, holding plates and folder base plates are optionally coordinated and then connected to a supporting member of a pocket folding device. After the patch pocket is set on the gage plate, the holding plate is put on the gage plate with the patch pocket between, so that the peripheral edge of the patch pocket is folded downward. Then, folders are slidably inserted along the back surface of the gage plate from the outside, thereby the peripheral edge of the patch pocket is folded back.
In such a device, since the holding plates are each fixed to the supporting member with bolts (for example, see U.S. Pat. No. 3,667,411), a tool such as a screwdriver and troublesome operation are required to exchange the holding plates. Moreover, the bolts are apt to loosen during the folding operation, resulting in deteriorating the accuracy of holding operation.
A holding device for holding a cloth is disclosed in the Japanese published unexamined utility model application No. 60-195686 in which a cloth holding plate is attached to a supporting member with an easy connecting mechanism. But in this holding device, the supporting member does not move upward nor downward in relation to the table of the machine. Further, the connecting mechanism is different from that of the present invention hereinunder described.